134 ENTOMOLOGICAL SOCIETY 



whole question is interesting and somewhat involved, on ac 

 count of the length of time covered by the appearance of the 

 different species, and while I felt impressed, on hearing the 

 paper, with the fact that a great deal of excellent original 

 work had been done at Champaign, and that the statements in 

 the current literature (which is so largely unacknowledged 

 compilation) would be effectually modified thereby, yet the 

 authoritative statements, which have been based on observa 

 tion, have not been materially impugned. 



Further investigation will doubtless show that the fall or 

 spring transformation is dependent to some extent upon lati 

 tude, and that, on this account, great irregularity may be 

 looked for. There is here a rich field for careful study and 

 experiment in different parts of the country, and it may turn 

 out that the three-year period, which is pretty fully sub 

 stantiated for the full life-cycle of some of the commoner 

 forms, may be either shortened or lengthened according to 

 latitude or species. 



In this connection I would also put on record the fact that, 

 according to Mr. Webster, from whom specimens have been 

 received as having been obtained from Lachnosterna larvae, an 

 undescribed Tachinid and Ophion bifoveolatum maybe added 

 to the list of parasites which I have already recorded as 

 attacking the larva of fusca. 



Mr. Townsend presented the following paper : 



NOTES ON NORTH AMERICAN TACHINIDiE SENS. LAT., 

 WITH DESCRIPTIONS OF NEW SPECIES. 



PAPER I. 

 BY C. H. TYLER TOWNSKND. 



In the first families of the Tachinida s. lat. much confusion 

 has resulted from the descriptions of the earlier authors, due 

 in great part to the fact that the two sexes of these flies ex 

 hibit marked differences, which would lead one to consider 

 them distinct species. From a critical study of descriptions 

 and material I have collected a considerable number of notes, 

 synonymical, relating to distribution, etc., which I here pre 

 sent, together with descriptions of some new species. 



Phasia atripennis Say. This is not a Phasia. The descrip 

 tion shows that the apical cell is petiolate, and compares the 

 venation to that of Phasia semicinerea Meig., which however 



